Roy Koushik, Chandran Dinu S, Deepak Kishore K
Department of Physiology, All India Institute of Medical Sciences - Central Armed Police Forces Institute of Medical Sciences Center, New Delhi, IND.
Department of Physiology, All India Institute of Medical Sciences, New Delhi, IND.
Cureus. 2025 Apr 21;17(4):e82752. doi: 10.7759/cureus.82752. eCollection 2025 Apr.
Pulse transit time (PTT) is crucial in developing non-invasive cuffless blood pressure (BP) measurement devices. Sympathetic activation, due to its effect on PTT, can lead to erroneous estimation of BP. Sympathetic activation might affect the PTT differentially depending on the site where PTT is measured in the upper limb. This study aimed to decipher regional variation in PTT in response to sympathetic activation in three segments of the upper limb arteries. Exposure to graded lower body negative pressure (LBNP) at hypotensive (-30 mmHg and -40 mmHg) and non-hypotensive (-10 mmHg and -20 mmHg) levels has been used to produce sympathetic activation.
This was a pilot study. Ten healthy subjects were recruited for the study, and recordings were done. Carotid, brachial, and radial pulse waveforms were recorded simultaneously by tonometry, and the finger pulse waveform was recorded by photoplethysmography (PPG). LBNP was applied at -10 mmHg, -20 mmHg, -30 mmHg, and -40 mmHg for two minutes. Carotid-brachial PTT (cbPTT), brachial-radial PTT (brPTT), and radial-finger PTT (rfPTT) were calculated.
cbPTT did not show any significant change, whereas both brPTT (0.02679±0.00635 sec at baseline vs. 0.02027±0.00662 sec at hypotensive LBNP; p=0.0386) and rfPTT (0.00908±0.00350 sec at baseline vs. 0.00585±0.00211 sec at hypotensive LBNP; p=0.003) showed a significant decrease in response to hypotensive LBNP. rfPTT (0.00908±0.00350 at baseline vs. 0.00534±0.00249s at non-hypotensive LBNP; p=0.0257) also showed a significant decline in response to non-hypotensive LBNP as well.
The current study reveals that in upper limb arteries, PTT response to LBNP shows regional variation with an accentuation of response from proximal to distal segments.
脉搏传播时间（PTT）对于开发无创无袖带血压（BP）测量设备至关重要。交感神经激活因其对PTT的影响，可能导致血压估计错误。交感神经激活可能根据在上肢测量PTT的部位不同而对PTT产生不同影响。本研究旨在解读上肢动脉三个节段中PTT对交感神经激活的区域差异。通过在低血压（-30 mmHg和-40 mmHg）和非低血压（-10 mmHg和-20 mmHg）水平下分级施加下体负压（LBNP）来产生交感神经激活。
这是一项初步研究。招募了10名健康受试者进行研究并进行记录。通过眼压测量法同时记录颈动脉、肱动脉和桡动脉的脉搏波形，通过光电容积脉搏波描记法（PPG）记录手指脉搏波形。在-10 mmHg、-20 mmHg、-30 mmHg和-40 mmHg下施加LBNP两分钟。计算颈动脉-肱动脉PTT（cbPTT）、肱动脉-桡动脉PTT（brPTT）和桡动脉-手指PTT（rfPTT）。
cbPTT未显示任何显著变化，而brPTT（基线时为0.02679±0.00635秒，低血压LBNP时为0.02027±0.00662秒；p = 0.0386）和rfPTT（基线时为0.00908±0.00350秒，低血压LBNP时为0.00585±0.00211秒；p = 0.003）在低血压LBNP时均显示出显著下降。rfPTT（基线时为0.00908±0.00350，非低血压LBNP时为0.00534±0.00249秒；p = 0.0257）对非低血压LBNP也显示出显著下降。
当前研究表明，在上肢动脉中，PTT对LBNP的反应存在区域差异，从近端节段到远端节段反应增强。
